Preparation Of Zinc Oxide/Metal Oxide Composite Fiber And Study On Its Degradation Mechanism Of Humic Acid

Today,with the rapid development of science and technology,renewable energy sources such as solar energy,wind energy,and tidal energy have begun to enter the public's field of vision.Because renewable energy has the advantages of low cost,low pollution and inexhaustible availability,it has gradually shown broad development prospects.The development of photocatalysis technology using solar energy is relatively rapid.Photocatalysis is a technology that photocatalysts make full use of solar energy to generate hydroxyl radicals that can degrade pollutants in water.At present,the development of single-component photocatalytic materials is more restricted and can no longer meet actual needs.Therefore,research on multi-component composite photocatalytic systems has emerged.The Zn O-Cu O,Zn O-Co₃O₄and Zn O-Ni O composite photocatalysts have a large visible light response range,which can effectively utilize solar energy and improve the photocatalytic degradation efficiency,and the fibrous structure of the material is more conducive to the system's adsorption of pollutants in the water.(1)Using zinc acetate dehydrate((CH₃COO)₂Zn·2H₂O),cupric acetate monohydrate(Cu(CH₃COO)₂·H₂O),and polyvinylpyrrolidone((C₆H₉NO)_n)as raw materials,precursor fibers of different proportions are prepared by electrospinning,and are directly calcined at different temperatures to synthesize Zn O/Cu O composite fibers material.The experimental results showed that the Zn O/Cu O composite fiber material was the optimal material for the system at a calcination temperature of550?and a zinc-cupric ratio of 1:1,but its efficiency of photocatalytic degradation of humic acid was not satisfactory,which was analyzed because the fiber morphology would have an effect on the efficiency of humic acid degradation.(2)Using zinc acetate dehydrate((CH₃COO)₂Zn·2H₂O),cobalt(II)acetate tetrahydrate(C₄H₆Co O₄·4H₂O),and polyvinylpyrrolidone((C₆H₉NO)_n)as raw materials,precursor fibers of different proportions are prepared by electrospinning,and are directly calcined at different temperatures to synthesize Zn O/Co₃O₄composite fibers material.The experimental results show that the composite fiber material with the zinc-cobalt ratio of 5:1 is the optimal product of the zinc-cobalt system when calcined at 600?;Comparing with the above zinc-copper optimal products,it can be found that the morphology of the composite fibers of the zinc-cobalt system is improved,but the efficiency of photocatalytic degradation of humic acid of the zinc-cobalt system is less different from that of the zinc-copper system,and a review of the literature shows that the material performance is related to the energy band structure of the composite system and the mode of photogenerated electron-hole pair transmission.(3)Using zinc acetate dehydrate((CH₃COO)₂Zn·2H₂O),nickel acetate tetrahydrate((CH₃COO)₂Ni·4H₂O),and polyvinylpyrrolidone((C₆H₉NO)_n)as raw materials,precursor fibers of different proportions are prepared by electrospinning,and are directly calcined at different temperatures to synthesize Zn O/Ni O composite fibers material.The experimental results show that the optimal product of znic-nickel system is the material obtained by calcination at 600?in the ratio of znic-nickel 1:5;the comparison of the above three systems shows that the morphology of the composite fiber of znic-nickel system is not significantly different from that of zinc-cobalt system,which is much better than that of zinc-cupric system,but the efficiency of photocatalytic degradation of humic acid of the composite fiber of znic-nickel system is much higher than that of the other two systems.In addition,the photocatalytic degradation mechanism of humic acid for the three systems was formulated.